'''
计算机         20091231112-蒋高强
'''
first = float(input("请输入第一个数: "))
second = float(input("请输入第二个数:"))
operator = input("请选择运算符:+ - */:")
if operator == '+':
    print(first + second)
elif operator == '-':
    print(first - second)
elif operator == '*':
    print(first * second)
elif operator == ' / ':
    if second == 0:
        print("除数不能为e")
    else:
        print(first / second)
